(a) Field of the Invention
The present invention relates to an optical wavelength and optical power measurement device. More particularly, the present invention relates to an optical wavelength and optical power measurement device using a sensing unit that is formed with a Dense Wavelength Division Multiplexing (DWDM) wavelength filter and a micro motor.
(b) Description of the Related Art
Nowadays, due to development of high speed Internet and increase of Internet traffic, transmitting capacity is being continuously increased. In order to satisfy the rapidly increasing transmitting capacity, by replacing old equipment with the latest equipment, Internet service providers are preparing for a future explosive increase in traffic, but due to a rapid increase in Internet Protocol Television (IPTV) service subscribers and high speed mobile communication networks such as a wideband Long Term Evolution (LTE) network, a high speed large capacity communication bandwidth is required.
In the late 1990s, a Wavelength Division Multiplexing (WDM) transmission system had a wavelength number of about 4 channels and 16 channels, a gap between channels of 200 GHz, and a transmission speed per channel of 2.5 Gbps, but currently, a demand for DWDM technology having 40-80 channels, a transmission speed of 10 Gbps or more, and a small channel gap of 50 GHz or 100 GHz is increasing.
Optical measurement technology includes the following measurement technology and measurement equipment.
That is, technology that measures intensity of an optical source is technology that changes and measures intensity of light with respect to an electrical signal using a photodiode made with a material such as Ge, InGaAs, and GaAs, and includes an optical power meter as measurement equipment.
Because a photodiode has different receiving sensitivity according to a wavelength, when an existing optical power meter previously discerns a wavelength of a light signal to measure for accurate measurement and measures optical power according to receiving sensitivity corresponding to the wavelength, the existing optical power meter can obtain an accurate value. A method of calculating final optical power by previously inputting a calibration of several much-used wavelengths such as 850 nm, 980 nm, 1310 nm, 1480 nm, 1550 nm, and 1610 nm and by multiplying the calibration by a measured optical power value has been generally used.
In a recent research result, as a method that is advanced from such a method, a method of using a wavelength dependant photodiode and a method of separately measuring optical power and an optical wavelength using an optical coupler and displaying an optical power value of a corresponding wavelength have been reported. Further, technology that analyzes the spectrum of light analyzes the spectrum according to a wavelength of light. Currently, a method of using rotated grating is generally used, but equipment thereof is expensive and is weak with respect to vibration.
As the equipment, an optical spectrum analyzer (OSA) is mostly used, and as equipment that accurately measures only a wavelength of light, a wavelength meter is used. Equipment that measures such an optical wavelength requires elaborate optical technology and a complex process, and thus the equipment has a drawback in that it has a large volume and high power consumption and that is weak against impact.
For reliable management of an optical subscriber network, monitoring of a wavelength and power of a light source depending on aging or a temperature change, wavelength alignment with a light source and a passing band of an MUX and DMUX that are affected by a peripheral temperature, and an optical fiber cutting situation of a transmitting line should be performed.
Upon installation and maintenance of an optical subscriber network to be performed in the future, when simply measuring only optical power, there are several difficulties. That is, E/G-PON technology, WDM-PON technology, or CWDM-PON technology should accurately ascertain a wavelength used as well as power of the wavelength.
At present, as equipment that can measure such an optical wavelength, an Optical Spectrum Analyzer (OSA) is used, but it may be used in a laboratory, and while it has been launched with a small size having mobility, a hand held type of unit thereof does not exist at present. The OSA is very expensive equipment at about 10,000-50,000 US dollars, and thus when configuring a network, the OSA may not be used in an external environment.
In general, an optical power meter is essential equipment for installation, inspection, and measurement of an optical communication system, and is used for determining whether power of a transmitting light signal and power of a receiving light signal are transmitted and received with appropriate intensity (optical power) of a light signal. A conventional optical power meter is a small and light measurement device and has been usefully used. Up to now, for communication, a wavelength of 1310 nm and a wavelength of 1550 nm have been mainly used. Particularly, in a subscriber network, a wavelength of 1310 nm is generally used.
However, it is expected that use of optical subscriber network equipment using a multi-wavelength will be rapidly increased. That is, because a WDM-Passive Optical Network (WDMPON), an E-PON, and a Coarse WDM-Passive Optical Network (CWDM-PON) system, which are optical subscriber network equipment that are commercially available, measurement equipment thereof is also required. When a wavelength of light to measure is known, a conventional optical power meter may perform accurate measurement.
As described above, for maintenance of a rapidly increasing DWDM optical communication system and transmission line, demand for a portable DWDM optical wavelength and optical power measurement device increases, but a conventional optical wavelength and optical power measurement device has only an optical wavelength and optical power measuring function, so when knowing a wavelength to measure, the conventional optical wavelength and optical power measurement device may measure accurate optical power, but it is difficult to produce a portable optical measurement device having a ferrule cross-section inspection function of an optical connector in the field in view of an existing DWDM wavelength filter module structure.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.